LAUSR

BACKGROUND The characteristics and comparison of countries regarding clinical trials for cancer were unknown. The World Health Organization-International Clinical Trials Registry Platform (WHO-ICTRP) are providing data from various countries and releases them generally in a downloadable format. We aimed to examine and descriptively identify the number of cancer clinical trials registered in the world and the fundamental characteristics in Asian 4 countries of China, India, Japan and South Korea, focusing on study characteristics, e.g., phase or targeted size, using the WHO-ICTRP. METHODS We extracted information on cancer clinical studies in the ICTRP database on September 20, 2019. Then, we performed a cross-sectional study on the annual number of registered studies and country, registered registry, phase, target sizes and sponsors. RESULTS We identified 80,677 cancer clinical studies. The annual number of registered cancer clinical studies significantly increased between 2005 and 2018 (3,172 to 8,156, β =382.2, 95% CI: 329.6, 434.8). Among the Asian 4 countries, the numbers of trials were significantly increasing in 2005-2018 (P<0.001). The characteristics on interventional studies for cancer differed in those 4 countries, e.g., the registered registries, phase and sponsors, compared with the US. CONCLUSIONS This study descriptively clarified an increase and the characteristics of cancer clinical trials in Asian 4 countries. It suggests to take that characteristics into account and select a database or data source discreetly for analysis of clinical trials, according to the purpose of the research and the required data.